v4l2: radio: measure time from start (refs #7400)

modules/access/v4l2/radio.c

@@ -34,10 +34,13 @@ struct demux_sys_t
 {
     int fd;
     vlc_v4l2_ctrl_t *controls;
+    mtime_t start;
 };
 
 static int RadioControl (demux_t *demux, int query, va_list args)
 {
+    demux_sys_t *sys = demux->p_sys;
+
     switch (query)
     {
         case DEMUX_CAN_PAUSE:
@@ -52,7 +55,7 @@ static int RadioControl (demux_t *demux, int query, va_list args)
             break;
 
         case DEMUX_GET_TIME:
-            *va_arg (args, int64_t *) = mdate ();
+            *va_arg (args, int64_t *) = mdate () - sys->start;
             break;
 
         /* TODO implement others */
@@ -96,6 +99,7 @@ int RadioOpen (vlc_object_t *obj)
 
     sys->fd = fd;
     sys->controls = ControlsInit (VLC_OBJECT(demux), fd);
+    sys->start = mdate ();
 
     demux->p_sys = sys;
     demux->pf_demux = NULL;